Part of a man's body was dumped on a recycling plant conveyer belt and discovered Friday, sparking an investigation into the fifth Seattle homicide this year.

Police did not immediately say if the body matched details from recent missing persons cases, and few details were immediately available, pending an autopsy and family notification.

The body was mixed with materials from a construction site.

Police were called to 7201 East Marginal Way S., at 10:48 a.m. Friday, and patrol officers called for homicide detectives after talking with workers.

"We don't believe that this person was killed here on site, but rather that they were transported here," Sgt. Sean Whitcomb said. "I can tell you that workers found the body on a conveyer belt."

The site is operated by CleanScapes, a waste-management and recycling firm. A spokesman for the company told KOMO/4 the body is not a CleanScapes employee. Police were expected to give more details in a Friday afternoon briefing.

The number of confirmed homicides in Seattle is at four so far this year - on pace to be the lowest annual rate since the 1940s. They include the death of vaudeville entertainer Robert Stabile, Capitol Hill beating of Zachary Lewis, South Seattle shooting of James Stapleton, and the domestic violence strangulation death of Rahel Afewerki Sium, accoridng to police and prosecutors.